Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Income Taxes

Tabular reconciliation of the total amounts of unrecognized tax benefits, excluding interest and penalties, at the beginning and end of the year

	2011			2010			2009
Total unrecognized tax benefits, January 1	$	127,595		$	201,216		$	63,318
Additions for tax positions of the currentyear	10,915			7,551			44,094
Additions for tax positions of prior years	—			—			98,942
Reductions for tax positions of prior years for:
Changes in judgment	(1,555		)	(11,017		)	—
Settlements with taxing authorities	(124		)	(62,199		)	(4,089		)
Lapses of applicable statute of limitations	(826		)	(7,956		)	(1,049		)
Total unrecognized tax benefits,December 31	$	136,005		$	127,595		$	201,216

Components of income tax expense

	Year Ended December 31,
	2011			2010			2009
Current:
Federal	$	(310	)	$	(108,827	)	$	(38,502	)
State	15,140			25,545			(38,080		)
Total current	14,830			(83,282		)	(76,582		)
Deferred:
Federal	159,566			260,236			62,874
State	16,626			10,911			42,618
Discontinued operations	—			(10,736		)	—
Total deferred	176,192			260,411			105,492
Total income tax expense	191,022			177,129			28,910
Less: income tax expense (benefit) ondiscontinued operations	7,418			16,260			(109,641		)
Income tax expense — continuing operations	$	183,604		$	160,869		$	138,551

Comparison of pretax income from continuing operations at the federal income tax rate to income tax expense - continuing operations

	Year Ended December 31,
	2011			2010			2009
Federal income tax expense at 35%statutory rate	$	188,733		$	177,002		$	138,110
Increases (reductions) in tax expenseresulting from:
State income tax net of federal income tax benefit	19,594			17,485			15,068
Credits and favorable adjustmentsrelated to prior years resolved incurrent year	—			(17,300		)	—
Medicare Subsidy Part-D	823			1,311			(2,095		)
Allowance for equity funds used duringconstruction (see Note 1)	(6,881		)	(6,563		)	(4,265		)
Palo Verde VIE noncontrolling interest (see Note 20)	(9,636		)	(7,057		)	(6,723		)
Other	(9,029		)	(4,009		)	(1,544		)
Income tax expense — continuing operations	$	183,604		$	160,869		$	138,551

Net deferred income tax liability recognized on the Consolidated Balance Sheets

	December 31,
	2011			2010
Current asset	$	130,571		$	124,897
Long-term liability	(1,925,388		)	(1,863,861		)
Deferred income taxes — net	$	(1,794,817	)	$	(1,738,964	)

Components of the net deferred income tax liability

	December 31,
	2011			2010
DEFERRED TAX ASSETS
Risk management activities	$	117,765		$	124,731
Regulatory liabilities:
Asset retirement obligation and removalcosts	236,739			222,448
Deferred fuel and purchased power	—			23,089
Renewable energy standard	19,722			18,749
Unamortized investment tax credits	31,460			642
Other	33,155			27,718
Pension and other postretirement liabilities	501,202			321,182
Real estate investments and assets held for sale	—			19,855
Renewable energy incentives	57,901			37,327
Credit and loss carryforwards	171,915			42,971
Other	73,759			68,684
Total deferred tax assets	1,243,618			907,396
DEFERRED TAX LIABILITIES
Plant-related	(2,446,908		)	(2,210,976		)
Risk management activities	(30,171		)	(30,125		)
Regulatory assets:
Allowance for equity funds used during construction	(33,347		)	(28,276		)
Deferred fuel and purchased power	(10,884		)	—
Deferred fuel and purchased power —mark-to-market	(30,559		)	(30,276		)
Pension and other postretirementbenefits	(408,716		)	(264,313		)
Other	(73,087		)	(77,078		)
Other	(4,763		)	(5,316		)
Total deferred tax liabilities	(3,038,435		)	(2,646,360		)
Deferred income taxes — net	$	(1,794,817	)	$	(1,738,964	)